CVE-2021-28703

MITRE NVD CVE.ORG Print: PDF PDF

Summary

CVECVE-2021-28703
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-12-07 12:15:00 UTC
Updated2024-02-04 08:15:00 UTC
Descriptiongrant table v2 status pages may remain accessible after de-allocation (take two) Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.

Risk And Classification

Problem Types: NVD-CWE-Other

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Xen Xen All All All All

References

ReferenceSourceLinkTags
Xen: Multiple Vulnerabilities (GLSA 202402-07) — Gentoo security security.gentoo.org
xenbits.xenproject.org/xsa/advisory-387.txt MISC xenbits.xenproject.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

LEGACY: Array

Legacy QID Mappings

  • 180382 Debian Security Update for xen (CVE-2021-28703)
  • 500803 Alpine Linux Security Update for xen
  • 501523 Alpine Linux Security Update for xen
  • 501801 Alpine Linux Security Update for xen
  • 502458 Alpine Linux Security Update for xen
  • 504546 Alpine Linux Security Update for xen
  • 710858 Gentoo Linux Xen Multiple Vulnerabilities (GLSA 202402-07)
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

CVE.report and Source URL Uptime Status status.cve.report